If thunder clouds are anywhere near, you should not be outside. For more information on lightning and related topics, check out … If you can hear thunder, the storm is near enough to you to pose an immediate threat; after the thunder ends, wait 30 minutes before resuming outdoor activities. (Be safe: you should be inside a house or permanent building, or a car.) You can easily figure out about how far away lightning is from where you are. You may see lightning right away, but the sound of the thunder travels five miles per second. Here we will consider the three forms of energy listed below: Some of the energy is in the form of visible radiation, which is what we see. After seeing a lightning bolt in the distance, count how many seconds it takes to hear the thunder. When you see the flash of a lightning bolt, you can start counting seconds and then divide to see how far away the lightning struck. Calculate the distance of lightning. Lightning is powerful. Thunder follows lightning. Do you ever see lightning without hearing thunder? Use this calculator when you see lightning and hear thunder to determine how far away it is! This application calculates the distance of a thunderstorm by measuring the time between the lightning and its thunder. Remember: When thunder roars, go indoors! Thunder and Distance to a Lightning Strike. Lightning Distance Calculator. Some call that "heat lightning," but it is really lightning that is over 15 miles away and too far away for you to hear the thunder… Anecdotally, there are many examples of people saying 'the storm was directly overhead or all-around and yet there was no thunder'. Its gnarled and hoary girth lay under a tangled old man’s beard of leaf and bough. Light travels much faster than sound. Lightning can travel long distances. The lightning and thunder are happening at the same time, but light reaches you instantly, while sound takes longer. Lightning at a sufficient distance may be seen and not heard; there is data that a lightning storm can be seen at over 160 km (100 mi) whereas the thunder travels about 32 km (20 mi). If it takes 10 seconds for the thunder to roll in, the lightning struck about 2 miles or 3 kilometers away. A lot of energy is released during a lightning strike. Using this relationship between seeing lightning and hearing thunder, you can determine a rough estimate of how far a thunderstorm is from your current location. In the centre of this large vale, quite some distance away, was a wizened oak tree.